Press guard



Aug. 14, 1945. J. B. MAG'IN' PRESS GUARD Filed July 7, 1944 2 Sheets-Sheet l INVENTOR. afzcozlifiyz'ra Aug. 14, 1945. J B, MAGIN 2,382,494

' PRESS GUARD Filed July 7 1944 2 Sheets-Shet 2 W I I IN V EN TOR.

Patented Aug. 14, 1945 PRESS GUARD Jacob B. Magin, Rochester, N. Y., assignor to Art in Buttons, Incorporated, Rochester, N. Y., a

corporation of New York Application July '7, 1944, Serial No. 543,930

7 Claims.

This invention relates to a press guard with particular reference to the type of hydraulic press in which a bed slowly moves upwardly into engagement with a stationary platen for compressing and hardening plastic products, and it has for its purpose to afford a simple and highly efiicient mechanism that effectually prevents injury if an operator inadvertently places a hand between the stationary platen and movable bed when the latter is ascending.

A more particular object of the invention is to afford a simple arrangement of parts that do not interfere with the normal operation or efficiency of the machine, and which when the conditions arise operate instantly to reverse upward travel of the bed and cause it to move downwardly to its initial inoperative position remote from the stationary platen.

A further purpose of the invention is to provide a structure that can be easily applied to existing machines without necessitating reorganization of the press or its hydraulic mechanism, and which protects an operator effectively against accident.

Another object of the invention is to 'afiord mechanism that will quickly effect reverse movement of the bed by engagement at any point longitudinally of the bed, so that no matter whether the operators hand is inserted centrally of the bed or at-one end thereof, the device insures the necessary control and reverse movement of the bed, as quickly and effectively from either end as at the longitudinal center thereof.

Still an additional purpose of the invention is to afiord a mechanism consisting of few parts and which can be economically produced and readily installed.

To these and other ends, the invention consists in the construction and arrangement of parts that will appear clearly from the following description when read in conjunction with the accompanying drawings, the novel features being pointed out in the claims following the specification.

In the drawings:

Fig. 1 is a view in front elevation showing a preferred embodiment of the invention as applied to a hydraulic press of conventional form;

Fig. 2 is an enlarged front elevation of the invention, showing the guard rail in elevated position;

Fig. 3 is a vertical sectional View on the line 3-3 of Fig. 2, and

Fig. 4 is a vertical sectional View on theline 4-4 of Fig. 1.

Referring more particularly to the drawings in which like reference numerals refer to the same parts throughout the several views, I designates the stationary platen of a conventional type of hydraulic press, while 2 is the movable bed which occupies its lowermost position when idle, and is movable slowly upwardly into engagement with the stationary platen when an operation is to be performed upon articles supported on the bed.

Such upward and downward travel of the movable bed is effected in a conventional way from cylinders and pistons at the top and bottom of the machine by suitable valve means including valves '4 and 5 connected by the link' 6 and operable through a suitable hand lever to govern the flow of water to the cylinders atthe bottom and top of the mechanism for moving the bed upwardly or downwardly, and in order to carry out the purposes of the invention, means are provided for quickly operating said valve means automatically to reverse movement of the upwardly traveling bed, when the guard rail is moved. I

This is preferably accomplished by a compressed air cylinder I within which travels a piston 8 connected by means of a chain 9 and'segment Ill to the valve 4. The cylinder I has connected thereto a compressed air line II within which is located a control valve indicated diagrammatically at [2, and normally closed, the valve I2 being opened when the guard rail is actuated to permit air pressure to pass to the cylinder 1 and operate the valve means and reverse movement of the bed. r v v To effect this, the valve I2 includes a projecting portion I3 which engages the cam surface I4 of an actuator or lever I5 which is movably supported and preferably pivotally mounted at I6 on a stationary support II. The actuator I5 extends downwardly and is provided at its lower end with a forked portion I8 that straddies and is slidable longitudinally on the guard rail I9, so that as the guard rail is lifted, the

actuator I5 is correspondingly elevated and tilted on its pivot I I5 to move the control valve while at the same time the forked lower end of the actuator I5 can slide endwise of the guard rail I9 to permit the action described.

The guard rail I 9 is positioned horizontally and movable in a vertical direction either bodily or to a greater extent at one end than at the other,

, eratively connected and to permit suchirregular movement, the ends of the guard rail l9 are pivotally connected to vertically slidable supporting members or plates 20 which engage stationary supports 2|. Each slidable plate 20 includes a slot 22 that is guided on a stationary pin 23 carried by the support 2|, while the outer edge of the movable plate ZDrests againsta guide or" stationary flange 24. v

In this way, acertain lost motion is permitted between the two ends of the guard rail, and while each supporting plate 20 is guided vertically, it is freely movable in a vertical direction and with it one end of the guard rail I9. Since the actuator I5 is slidably movable endwise of the guard rail [9, it will be seen that the guard rail can easily be lifted by engaging it at the center, at either end, or at any point therebetween, and

regardless of where the guard rail is contacted by the operator, it moves upwardly and carries with it the actuator 1'5 to operate the control valve in the air line I l and move the valve means to reverse movement of the bed instantly and o'arrythe latter down to its inoperative position away from the stationary platen.

The guard rail I9 is preferably located somewhat below the stationary platen l and forwardly thereof, and in order to prevent an operator from inserting a hand orfingers between the guard rail and the stationary'platen I', supplemental guarding elements or fences are provided in the form of wire frames 25 located on opposite sides of the actuator l5 and fixedly attached to the guard rail IS. The wire frames 25' occupy substantially the greater part of the area between the guard rail l9 and the stationary platen I and are effective to prevent an operator from inserting his hand-immediately under the statlonary platen.

In operation, if during the upward travel of the movable bed 2 an operator inadvertently positions his hand over the bed to adjust work or for some other reason, as the bed travels upwardly, the operators hand strikes 'the'guard rail 19, moving the latter upwardly and with it the actuator I5, which swings onit's pivot and actuates the control valve l2. When the latter is opened, air pressure is released into cylinder I and immediately causes operation of the valve means which reverses travel of the bed '2 instantaneously, stopping its upward travel and causing it to move downwardly "to its initi'al'position,- where it remains until the operator again actuates the valve means to elevate the bed.

While the invention has been described with reference to the details of'con'structlo'n herein shown, it is not confined to the precise arrangement described, and the application is intended to cover such modifications and departures as may come within the intent of the improvement or the scope of the following claims.

I claim:

1. In a hydraulic press of the type including a bed which moves upwardly into engagement with a stationary -platen and returns to initial positionduring each cycle and valve mechanism controlling the movement of water for operating the bed upwardly and downwardly, guard mechani'sm comprising a compressed air cylinder opto said valve means for 0perating it, a compressed air line connected with said cylinder, a compressed air valve in said air 'line normally in closed position, a horizontally positioned guard rail which is stationary during the normal operation of the bed, an actuator mova ble into engagement with said compressed air atively connected to said valve means for operating it, a compressed air line connected with said cylinder, a compressed air valve in said air line normally in closed position, a horizontally positioned guard rail which is stationary during the normal operation of the bed, a pivoted actuator movable into engagement with said compressed air valve to move the latter to open position and having a forked lower end slidably engaging said guard rail, vertically movable supporting plates pivotally connected to the endsof the guard rail permitting greater movement of one end of the guard rail than the other, said supporting plates having slots therein, guides for said plates, and plintsS carried by said guides and engaging said s o 3. In a hydraulic press of the type including a verticall movable bed which moves upwardly into engagement with a stationary platen and returns to initial position during each cycle and valve means governing the movement of water for operating the bed upwardly and downwardly, guard mechanism comprising a horizontally positioned guard rail which is stationary during the normal operation of the'bed and located forwardly of said movable bed and beneath the limit of its upward travel, an actuator operatively associated with and moved by said guardrail, a control valve positioned for engagement and operation by saidactuator, a compressed air line in which said control valve is located, a cylinder communicating with said: compressed air line, and

a piston in said cylinder connected to the aforesa d valve means whereby the latter is operated and the direction of movement of the bed is reversed when said guard rail is engaged and moved upwardly.

4. In a hydraulic press of the type including a vertically movable bed which moves upwardly into engagement with a stationary platen and return to initial position during each cycle and valve means'governing the movement of water for operating the bed upwardly and downwardly,

" guard mechanism comprising a horizontally positioned guard rail which is stationary during the normal operation of the bed and located forwardly of said movable bed and beneath the limit of its'upward travel; a pivoted lever havment of the bed is reversed when said guard rail is engaged and moved upwardly.

5. Ina hydraulic press of the type including a vertically movable bed which moves upwardly into engagement with a stationary platen and returns to initial position'during each cycle and valve means governing the movement of water for operating the bed upwardly and downwardly, guard mechanism comprising a horizontally positioned guard rail which is stationary during the normal operation of the bed and located forwardly of said movable bed and beneath the limit of its upward travel, an actuator operatively associated with and moved by said guard rail, vertically movable supporting members ivotally connected to the ends of the guard rail permitting greater movement of one end of the guard rail than the other, a control valve positioned for engagement and operation by said actuator, a compressed air line in which said control valve is located, a cylinder communicating with said compressed air line, and a piston in said cylinder connected to the aforesaid valve means whereby the latter is operated and :the direction of movement of the bed is reversed When said guard rail is engaged and moved upwardly.

6. In a hydraulic press of the type including a vertically movable bed which moves upwardly into engagement with a stationary platen and returns to initial position during each cycle and valve means governing the movement of water for operating the bed upwardly and downwardly, guard mechanism comprising a horizontally positioned guard rail which is stationary during the normal operation of the bed and located forwardly of said movable bed and beneath the limit of its upward travel, a pivoted lever having its lower end operaitively associated with said guard rail and actuated thereby, vertically movable supporting members pivotally connected to the end of the guard rail permitting greater movement of one end of the guard rail than the other, a control valve in the path of movement of the upper end of said lever and positively operated thereby, a compressed air line in which said control valve is located, a cylinder communicating with said compressed air line, and a piston in said cylinder connected to the aforesaid valve means whereby the latter is operated and the direction of movement of the bed is reversed when said guard rail is engaged and moved upwardly.

7. In a hydraulic press of the type including a vertically movable bed which move upwardly into engagement with a stationary platen and returns to initial position during each cycle and valve means governing the movement of water for operating the bed upwardly and downwardly, guard mechanism comprising a horizontally positioned guard rail which is stationary during the normal operation of the bed and located forwardly of said movable bed and beneath the limit of its upward travel, a pivoted lever having a forked lower end sliclably engaging said guard rail at its \central portion, vertically movable supporting plates pivotally connected to the ends of the guard rail permitting greater movement of oneend of the guard rail than the other, said supporting plates having slots therein, guides for said plates, pins carried by said guides and engaging said slots, a control valve in the path of movement of said lever and positively operated thereby, a compressed air line in which said control valve is located, a cylinder communicating with said compressed air line, and a piston in said cylinder connected to the aforesaid valve means whereby the latter is operated and the direction of movement of the bed is reversed when said guard rail is engaged and moved upwardly.

JACOB B. MAGIN. 

